1. Field of the Invention
The present invention generally relates to an energy system, and more particularly, to a solar energy system.
2. Description of Related Art
Solar energy is never exhausted and pollution-free, which draws people's attention to solving problems of pollution and lack of energy supply confronted by the current petrochemical industry. A solar panel is able to directly convert sunlight energy into electric energy by means of photovoltaic (PV) cells thereof. In this regard, how to fully take advantage of the sunlight to get better photoelectric conversion efficiency has become very significant.
In general, a solar panel made of a silicon-based material usually has a photoelectric conversion efficiency of 20-30% only. Such low photoelectric conversion efficiency is mainly caused by the energy conversion limitation that the current solar panel only absorbs and converts partial sunlight energy with an energy band gap of 1.1 eV. In other words, only a part of the sunlight with a center wavelength shorter than 1100 nm can be absorbed, and the shorter the wavelength is, the poorer the corresponding photoelectric conversion efficiency is. Based on the above-described situation, most energy of the sunlight striking onto the solar panel is wasted and unable to be converted into electric energy, and the light unconverted by the solar panel produces heat on the solar panel to increase the temperature thereof only. Among various solar panels, a high concentration photovoltaic panel (HCPV panel) is most sensitive to the high temperature impact. In order to avoid a solar panel from having an overly high temperature, the solar panel usually needs to employ a cooling system, which thereby increases costs of fabricating the solar panel.
In short, a conventional solar energy system not only is unable to effectively convert the sunlight energy for improving the low total photoelectric conversion efficiency, but also increases the fabrication costs because of the requirement for the disposition of the cooling system.